Quick acting clamp



p 1940- J. H. HARRISON Y 2,197,128

QUICK ACTI-NG cum? Filed April 10, 19:59

INVENTOR 6 17 15 BY Q... a) I I ATTORNEY Patented Apr. 16,1940

UNITED" STATES PATENT OFFICE This invention relates to hand actuatedclamps, the principal object of my invention'being to provide a toolofthis nature so constructed that it may be operated, "either to providea [clamping hold or to release-such hold, with one hand.

1 Another object is to provide a toolhaving a reciprocating oroscillating operating or control member and ,to arrange the operatingparts in connectionwith such member that successive movements of thesame in'the same direction alternately effect the clamping and releaseof the of times the tool may be engaged with or released from the workduring the performing of the necessary operations thereon. V

The tool is thus particularly adapted for repe- 25 titious use on workof a given thickness, as when holding plates and the like together forwelding or drilling at different points in their extent, or in any casewhere repeated but intermittent clamping oi the work is desirable. I

A further object of the invention is to produce a simple device and yetone which will be exceedingly effective for the purpose for which it isdesigned.

These objects I accomplish by means of such structure and relativearrangement of parts as will fullyappear by a perusal of the followingspecificationv and claims.

In the drawing similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a side elevation of the tool with the jaws in clampingposition.

Figure 2 is a fragmentary section showing the control cam in theposition occupied in Fig. 1.

Figure 3 is a similar view showing the position of the control cam whenthe jaws are released or relatively separated.

Figure 4 is a fragmentary sectional plan on line 4-4 of Fig. 1.

- Referring now more particularly to the characters of reference'on thedrawing, the body of the tool comprises a pair of transversely spacedside ears I which depend from one end of and are rigid with a handle 2,and .are also rigid with a boss 3 disposed ahead of the handle and earsI above the latter.

Adjustably threaded through the boss so as to be disposed substantiallyat right angles to the handle is a screw 4 provided at its upper end,above the head, with a suitable cross handle 5 and with a clamping nut lto engage the head.

The lower end of the screw is provided with a jaw element 1.

Projecting forwardly from between the ears I at their lower end is anarm 8, carrying an upstanding iaw element 9 facing to and adapted toaline when in operation, with the element I. This arm is pivotedintermediate its ends on a pin l mounted on the members I, and the uppersurface of the portion of said arm between the ears is formed as a flatledge ll. Turnably mounted between the ears I above the arm on a shafti2 is a cam i3 having a plurality of evenly spaced high and low points Hand L respectively thereabout. Preferably the cam is in the form of ahexagon with its corners flattened somewhat. When any high point engagesledge H in proper radial relation, the arm 8 is obviously swung upwardat its outer end, and the jaw elements I and 9 are then alined as shownin Fig. 2. When a low point engages the arm, the outer end of the latterwill of course be lowered and the jaw'elements correspondingly separatedas shownin Fig. 3. A spring H of suitable form acts against the arm tohold the same against the cam, and causes ledge H to follow and alwaysengage either the high or low points of the cam as the latter rotates.

It is to be understood that the radius of all the high points is thesame, and this is also true of the low points. The jaw elements 1 and 9will therefore be the same distance from each other when any high pointof the cam is riding ledge I I. Such rotation of the cam, to control thesetting of arm 8 and jaw element 9 relative to the fixed jaw element 1,is controlled by the following means:

The shaft l2 projects at both ends outwardly from ears I, and fixed onone projecting portion is a ratchet wheel l having the same number ofteeth as the total number of high and low cam points, and which facerearwardly at the top of the wheel. Pivoted on the shaft l2 adjacentwheel I5 is an arm l6, carrying a pawl I! to engage the teeth of wheell5 at the top. This arm rearwardly of ears I is bent laterally and thenextends as a handle l8 directly under handle 2. A spring 19 between thehandles tends to hold them spread, and approach of the handles islimited by a stop 20 onone handle.

The are of swinging movement of the handle l8, and of the pawl, is notless than the arc of spacing between adjacent ratchet teeth, and lessthan the spacing between two teeth. The stop 20 is set so that when thehandles are at their limit of approach, either a high or low cam pointis exactly centered on the ledge H.

The shaft 12 is mounted with a close running fit, but in order toprevent retractive rotation thereof when the pawl is dragging over theratchet wheel, said shaft (which is in the form 01' a bolt) is providedon the projecting end thereof opposite the ratchet wheel, with a nut andspring washer unit 2| engaging the adjacent ear I.

In operation the nut B is first loosened and the screw 4 retracted sothat when the handles are spread and the jaw element 9 lowered, theplates P or other work to be clamped may project between the jawelements. The handles are then brought together, bringing jaw element 8toward the work and the screw 4 is then advanced until the work isfirmly clamped between the jaw elemerits. The lock nut 6 is then set tohold the screw 4 against movement. To release the clamping hold, it isonly necessary to allow handle is to drop away from handle 2, and thenagain bring the handles together. The drop of handle it does not affectthe position of the cam, since the pawl merely drags over the ratchetwheel. The opposite movement of said handle however again impartsrotation to the rachet wheel, shifting the same from a high to a lowengaging point: The arm '8 thus drops, moving jaw element '9 away fromand releasing the work. Two more oscillating movements of handle l8again brings a high cam point into operation, and since all the highpoints are the same arcuate distance from the axis of rotation of thecam, the jaw elements will then always be set at the same spacing fromeach other and the work will be clarn'ped with the same effectivenesswith each return of the jaw elements to clamping position. The handlesare arranged so that even when fully spread, they may be readily grippedin one hand, and thus the operation of the tool, through its recurringclamping and releasing movenients, can be conveniently eifected with onehand, leaving the other hand free for other uses.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forthherein. While this specification sets forth indetail the present and preferred construction of the device, still inpractice such deviations from such detail may be resorted to as do notform a departure from the spirit of the invention, as defined by theappended claims. Having thus ,described myinvention, what I claim as newand useful and desire to secure by l.etters.Patent isi.

1. A clamping tool comprising a body having a handle projecting from oneend thereof, a fixed jaw elementmounted on the body at the end thereofopposite the handle, a movable jaw element mounted on the body inopposed cooperating relationship to the fixed jaw, a member mounted foroscillation on the body and means between "said'rnember and the movablejaw to move the lattertoward the fixed jaw with alterriate movements ofthe'me'mber in'one direction and to move"said movable jaw away from thefixed jaw with the intermediate movements of the member in said onedirection.

2. A tool as in claim 1, in which said member includes a handlepositioned relative to the first named. handle to be engaged in commonby one hand 0.1: an operator.

3. A clamping tool comprising a body having ahandle projecting from oneend thereof, a'fixed jaw element mounted -on the body, at the endthereof opposite the handle, a movable jaw element disposed in opposedcooperating relationship to the fixed jaw, an armon one end of which themovable jaw element is fixed, means mount-' ing the arm lntermediateits'ends' on. the body for rocking movement, another handle pivoted.

on the body in cooperating relationship to the first handle foroscillating movement toward or from the same and means between saidother handle and the arm to rock the same in one direction withalternate oscillating strokes in one direction, and to cause said arm torock in the other direction with the intermediate strokes of the otherhandle in said one direction.

4.. A tool as in claim 3, in which said last named means includes arotary cam mounted on the body and engaging the arm, said cam beingformed with a plurality of high and low points about its circumference.

' v5. A clamping tool" comprising a body having a handle projecting fromone end thereof, a fixed jaw element-mounted on the body at the endthereof opposite the handle, a movable jaw element disposed in opposedcooperating relationship to the fixed jaw, an ar'm onone end of whichthe movable jaw element is fixed, means mounting the arm on the body forrocking moyement, av rotary cam mounted at a pointthereon' such astorock the arm with rotation of the cam, said cam being formed with aplurality of alternating high and low points, the high points being 'allequidistant from the axis of the cam and means to intermittently rotatethe cam predetermined arcuate amounts.

6. A clamping tool comprising a body having a handle projecting fromoneend thereof, a"'fixed jaw element mountedon the bodyat the endthereof opposite the handle; a movable jaw element disposed in opposedcooperating relationship to the fixed jaw, an arm on one endf'of whichth movable jaw element is fixed, means mounting the arm intermediate itsends on the body for. rocking movement, a rotary ,c'am mountedonthe bodyand engaging thearm on the 'same sidebut adjacent the end, thereofopposite that from which the jaw element projects, said cam being formedwith a plurality of evenly spacedand alternating high and low points,another handle pivoted on the body in common with but turnable relativeto the cam, a ratchet. wheel fixed with the cam and the arcuate spacingof whose teeth is the same as that between adjacent cam points and apawl mounted on said other handle and engaging the ratchet wheel; saidother handle being arranged for oscillating movement sufficlent toadvance the ratchet wheel the full distance between adjacent, teeth onlywith each movement of said handle in one direction.

'7. A tool as in claim 6, in which said other handle is disposedrelative to thefirst handle so as to be engaged in commpnby, one hand ofan operator; the pawl being positioned to advance the ratchet wheel withmovement of said other handle toward the first handle.

8. A tool as in claim 6, in which said other handle is disposed relativeto the first handle so as to be engaged in common by 'one hand of anoperator; the pawl being positioned to advance the ratchet wheel withmovement of said other handle toward the first handle, andmeans to limitthe movement of said other handle toward the first handle;"'thecam'being 'disposed relative to said other handle when at itslimit ofmove- JOHN H. HARRISON.

